The present invention relates to an improvement in an engine starter.
As a general type of a starter mounted on a small-sized engine, there has so far been known such one as shown in FIG. 1.
In FIG. 1, a crank shaft 2 extends from an internal combustion engine 1 (hereinafter referred to as an engine) and a flywheel 4 with a ring gear 3 fitted at its outer circumference is secured at the free end of the crank shaft 2. A starter motor indicated, as a whole, by a reference nuemral 5 is constituted by a d.c. motor 6, an overrunning clutch 7 and the rotary shaft 8 of the d.c. motor 6. The overrunning clutch 7, provided with a lever-engaging slot 7a, has a spline-connection with the rotary shaft 8 in a slidable manner in the axial direction. A pinion 10 is secured to the output rotary shaft 9 so as to be capable of interlocking with the ring gear 3. A shift lever 11 has a pivotal point 11a supported by a frame (not shown), a lower end part inserted into the lever-engaging slot 7a of the overrunning clutch 7 to be engaged therewith, and an upper end part inserted into the plunger 13 of an electromagnetic switch 12 to be engaged therewith.
In the engine starter having the structure as above-mentioned, when the electromagnetic switch 12 is actuated by feeding current, the plunger 13 is attracted into a casing (not shown) with the consequence that the shift lever 11 is forced to turn in the clockwise direction in the figure around the pivotal point 11a to urge the overrunning clutch 7 on and along the rotary shaft 8 forwardly in the state as shown in FIG. 1, namely toward the left side in FIG. 1 whereby the pinion 10 is brought to interlocking with the ring gear 3. As soon as the pinion 10 interlocks with the ring gear 3, a main contact (not shown) of the electromagnetic clutch 12 is closed to cause the d.c. motor 6 to generate torque. The torque of the d.c. motor is transmitted to the ring gear 3 through the rotary shaft 8, the overrunning clutch 7, the output rotary shaft 9 and the pinion in this order, with the result that the crank shaft 2 is actuated to be driven and the engine 1 is started. After starting of the engine 1, the actuation of the electromagnetic switch 12 is removed by breaking the current. Then, the plunger 13 returns to the state as shown in FIG. 1 by the repulsive force of a spring (not shown) which is housed in the casing of the electromagnetic switch 12 and the shift lever 11 moves the overrunning clutch 7 backward (on the right hand in FIG. 1) along the rotary shaft 8 to disconnect the pinion 10 from the ring gear 3 thereby returning it into a standing condition as shown in FIG. 1.
Thus, since the conventional device is constructed in such a manner that the d.c. motor 6 is actuated by feeding a relatively large current from a battery (not shown) mounted on a car for each time of starting the engine 1, excessive discharge is caused in the car battery when start and stop of the engine 1 is repeated during a short time thereby inviting a rapid reduction in the starting function of the engine. Further, when the engine is restarted immediately after its stoppage, the resistance of a circuit becomes large due to a high temperature around the starting system whereby the engine sometimes could not be started.